14-3-3 proteins stabilize LGI1-ADAM22 levels to regulate seizure thresholds in mice
Norihiko Yokoi,
Yuko Fukata,
Kei Okatsu,
Atsushi Yamagata,
Yan Liu,
Makoto Sanbo,
Yuri Miyazaki,
Teppei Goto,
Manabu Abe,
Hidetoshi Kassai,
Kenji Sakimura,
Dies Meijer,
Masumi Hirabayashi,
Shuya Fukai,
Masaki Fukata
Affiliations
Norihiko Yokoi
Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
Yuko Fukata
Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan; Corresponding author
Kei Okatsu
Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
Atsushi Yamagata
RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
Yan Liu
Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
Makoto Sanbo
Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
Yuri Miyazaki
Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
Teppei Goto
Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
Manabu Abe
Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
Hidetoshi Kassai
Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
Kenji Sakimura
Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
Dies Meijer
Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
Masumi Hirabayashi
Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan; Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
Shuya Fukai
Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
Masaki Fukata
Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan; Corresponding author
Summary: What percentage of the protein function is required to prevent disease symptoms is a fundamental question in genetic disorders. Decreased transsynaptic LGI1-ADAM22 protein complexes, because of their mutations or autoantibodies, cause epilepsy and amnesia. However, it remains unclear how LGI1-ADAM22 levels are regulated and how much LGI1-ADAM22 function is required. Here, by genetic and structural analysis, we demonstrate that quantitative dual phosphorylation of ADAM22 by protein kinase A (PKA) mediates high-affinity binding of ADAM22 to dimerized 14-3-3. This interaction protects LGI1-ADAM22 from endocytosis-dependent degradation. Accordingly, forskolin-induced PKA activation increases ADAM22 levels. Leveraging a series of ADAM22 and LGI1 hypomorphic mice, we find that ∼50% of LGI1 and ∼10% of ADAM22 levels are sufficient to prevent lethal epilepsy. Furthermore, ADAM22 function is required in excitatory and inhibitory neurons. These results suggest strategies to increase LGI1-ADAM22 complexes over the required levels by targeting PKA or 14-3-3 for epilepsy treatment.
